Belt feeder centering method and apparatus

Abstract

A method and apparatus are provided for positioning sheets of material on a belt feeder for transporting the material through a cutter toward a tire-processing apparatus. The material has a front-edge portion which is centered by using edge-position control, and side portions which are centered by using center-position control. Also, the material, as cut, will have a rear-edge portion, the centering position of which is controlled by edge-position control.

What is claimed is: 
     
       1. A method for centering material on a belt feeder having a center position, said material having side edges and a front-edge portion, comprising the steps of: moving said material along a desired path on said belt feeder;   measuring the width of said front-edge portion of said material at a preselected location along said path using edge-position control as said material is moved along said feeder;   measuring the position coordinates of both side edges of said material at said preselected location using center-position control after said front-edge portion has moved past said location;   calculating the center position of said material based on said position coordinates; and   moving said material in a direction to have said center position of said material coincide with said center position of said belt feeder, if necessary.   
     
     
       2. A method, as claimed in claim 1, wherein said material has a rear-edge portion and the width of said rear-edge portion is measured at said preselected location using edge-position control when said rear-edge portion reaches said location. 
     
     
       3. A method, as claimed in claim 1, wherein the width of said front-edge portion of said material increases as the material is moved along said path. 
     
     
       4. A method, as claimed in claim 2, wherein the width of said rear-edge portion of said material decreases as the material is moved along said path. 
     
     
       5. Apparatus for centering material on a belt feeder having a center position, said material having side edges and a front-edge portion, said apparatus comprising: conveyor means for moving said material along a desired path on said belt feeder;   means for measuring the width of said front-edge portion of said material at a preselected location along said path using edge-position control as said material is moved along said feeder;   means for measuring the position coordinates of both said edges of said material at said preselected location using center-position control after said front-edge portion has moved past said location;   means for calculating the center position of said material based on said position coordinates; and   means for moving said conveyor in a direction to have said center position of said material coincide with said center position of said belt feeder, if necessary.   
     
     
       6. Apparatus, as claimed in claim 5, wherein said material has a rear-edge portion and wherein means are included for measuring the width of said rear-edge portion at said preselected location when said rear-edge portion reaches said location. 
     
     
       7. Apparatus, as claimed in claim 5, wherein the width of said front-edge portion of said material increases as said material is moved along said path. 
     
     
       8. Apparatus, as claimed in claim 6, wherein the width of said rear-edge portion of said material decreases as said material is moved along said path. 
     
     
       9. Apparatus, as claimed in claim 5, wherein a material cutter is arranged along said path on said belt feeder, said cutter having an entry side and an exit side; first guiding means arranged at said entry side of said cutter for centering said material on said belt feeder; and   second guiding means arranged at said exit side of said cutter for aligning at least one of said side edges of said material along a predetermined path.   
     
     
       10. Apparatus, as claimed in claim 9, wherein said first guiding means includes a plurality of rollers, at least one of which respectively contacts each of said side edges of said material; and said second guiding means includes at least one roller which contacts at least one of said side edges of said material.   
     
     
       11. Apparatus, as claimed in claim 5, wherein said means for measuring the position coordinates of both said edges of said material includes an image sensor arranged at said preselected location.